This invention relates generally to a burner assembly and, more particularly, to a burner assembly for a radiant tube heating system.
A typical radiant tube heating assembly includes a U-shaped radiant tube located within a furnace and having input and return legs extending through the walls of the furnace. As gas-fired burner assembly is located in the input leg of the radiant tube and produces a high temperature flame which effects heating of the tube. Exhaust gases flow into the return leg and are discharged from the system through a flue adjacent the free end of the return leg.
To effect efficient heating and clean combustion, it is desirable that the high fire flame of the burner assembly just reach the return bend of the U-shaped radiant tube such that fingers of the flame are just visible in the return leg of the tube. In most commercially available radiant tube heating systems, combustion air is premixed with the gaseous fuel upstream of the burner nozzle of the burner assembly. The length of the flame is controlled by adjusting the ratio of combustion air to fuel and is set on a trial and error basis by changing the fuel/air ratio while viewing the flame length down the return tube.